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  <script>
    var arrayPairSum = function (nums) {
      nums.sort((a, b) => a - b);
      let ans = 0;
      for (let i = 0; i < nums.length; i += 2) {
        ans += nums[i];
      }
      return ans;
    };
    console.log(arrayPairSum([1, 4, 3, 2]));
  </script>
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